Why does a gravitating body ONLY do work on an object when it is moving? The gravitational field is there all the time.

Because a stationary object in the gravitational field will FALL unless it is restrained by a force. Then it won't. (Say.) That force is unmoving and therefore no work is being done.

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Forget about nerves and ATP, consider the following example. I am on a steep hill in my car and I take the handbrake off. Instead of rolling back down the hill I have my clutch part way out and the accelerator pedal slightly depressed. The revs of the engine combined with clutch control stops the vehicle rolling back down the hill. The car engine is therefore doing work but yet the car is not moving. How is this possible?

I searched in vain for a good analogy for muscular effort the other night. This is it. When a human lifts a weight, his muscular function is exactly analogous to a slipping clutch. Humans do work to create a force. Machines don't.

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Going back to the example of the rock sat on the surface of the Moon, on a quantum level you could indeed consider that the gravitational field was doing work on the stationary rock.

That's a FAIL. It's just exerting a force upon it.

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Between atoms there is mainly space and what stops the atoms of the rock and the lunar surface combining in the gravitational field is an electrostatic repulsion in the other direction.

ALL gravitational fields pass through ALL materials without exception. You would get NOTHING in a physics paper for this.

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This electrostatic repulsion is continuous and therefore the electric charges in the atom are continually doing work.

The electrostatic repulsion is FRICTIONLESS. Quantum rules. No work can ever be done upon them, (let's not consider electrochemical energies right now) except in the following manner:
ANY work done in the readjustment of an electron orbit will either require a photon input or produce a photon as output.
No atomic nuclei are ever exposed outside of nuclear fission or fusion.
All we EVER "feel" are the repulsions of such electron orbits.
EVEN when a tank is penetrated by an anti-tank round (possibly one of the hardest man-made impacts), NO nucleus of an atom of the metal of the round gets anywhere near contacting any nucleus of an atom of the metal of the tank.

Because a stationary object in the gravitational field will FALL unless it is restrained by a force. Then it won't. (Say.) That force is unmoving and therefore no work is being done.

I searched in vain for a good analogy for muscular effort the other night. This is it. When a human lifts a weight, his muscular function is exactly analogous to a slipping clutch. Humans do work to create a force. Machines don't.

That's a FAIL. It's just exerting a force upon it.

ALL gravitational fields pass through ALL materials without exception. You would get NOTHING in a physics paper for this.

The electrostatic repulsion is FRICTIONLESS. Quantum rules. No work can ever be done upon them, (let's not consider electrochemical energies right now) except in the following manner:
ANY work done in the readjustment of an electron orbit will either require a photon input or produce a photon as output.
No atomic nuclei are ever exposed outside of nuclear fission or fusion.
All we EVER "feel" are the repulsions of such electron orbits.
EVEN when a tank is penetrated by an anti-tank round (possibly one of the hardest man-made impacts), NO nucleus of an atom of the metal of the round gets anywhere near contacting any nucleus of an atom of the metal of the tank.

Well how about the following example. Two teams contest in a tug of war. While both sides take the strain pulling either end of the rope and the red rag tied at the centre of the rope is not moving, you claim no work is being done. According to work done = force x distance, work is only ever done when the red rag is moving. Bravo, bravo!

I could go on and on, there are so many other examples I just couldn't think of them all!

Well how about the following example. Two teams contest in a tug of war. While both sides take the strain pulling either end of the rope and the red rag tied at the centre of the rope is not moving, you claim no work is being done. According to work done = force x distance, work is only ever done when the red rag is moving. Bravo, bravo! I could go on and on, there are so many other examples I just couldn't think of them all! And you claim I have a fail in physics?

That again is an example of musculature emulating a slipping clutch, and has nothing to do with simple mechanics. Do you KNOW how muscles work?
Engineering solved three hundred years ago the problem of how to avoid human beings doing WORK while in a motionless state. They used a RATCHET. As in a vehicular handbrake lever. The pawl locks the mechanism which remains under tension.
Because you wilfully will not understand the science of mechanics you believe the millions of engineers who preceded you have all missed something essential.
Any year ten science book will show you otherwise.
Waste your own time attempting to prove it wrong if you must. You won't.
The principle of how work is done is one of the most basic principles in Physics. It's less than 1% of all the physics theory there is, yet underlies all else.
If you cannot understand this clearly you're in a world full of pain, full of misconception after misconception. Yes, FAIL.

That again is an example of musculature emulating a slipping clutch, and has nothing to do with simple mechanics. Do you KNOW how muscles work?
Engineering solved three hundred years ago the problem of how to avoid human beings doing WORK while in a motionless state. They used a RATCHET. As in a vehicular handbrake lever. The pawl locks the mechanism which remains under tension.
Because you wilfully will not understand the science of mechanics you believe the millions of engineers who preceded you have all missed something essential.
Any year ten science book will show you otherwise.
Waste your own time attempting to prove it wrong if you must. You won't.
The principle of how work is done is one of the most basic principles in Physics. It's less than 1% of all the physics theory there is, yet underlies all else.
If you cannot understand this clearly you're in a world full of pain, full of misconception after misconception. Yes, FAIL.

Okay JazzRoc if you're so sure of yourself then explain away my original example in my first post. You haven't done this yet.

Indeed this is my best example:

Two men of exactly the same physical strength push two differing weights mounted on sets of wheels. If the weight pushed by the second man is exactly double that of the firstís and is pushed through the exact same distance, each man could not have performed the exact same amount of work while pushing with the exact same force. On the contrary the second man would have needed to have pushed the heavier weight for a longer duration of time using the exact same force in order to have moved it through the same unit distance (as a result of its acceleration being less from F = ma), and this would have resulted in more work having been done. This contradicts the accepted relation, Work Done = Force x Distance.

Two men of exactly the same physical strength push two differing weights mounted on sets of wheels. If the weight pushed by the second man is exactly double that of the firstís and is pushed through the exact same distance, each man could not have performed the exact same amount of work while pushing with the exact same force. On the contrary the second man would have needed to have pushed the heavier weight for a longer duration of time using the exact same force in order to have moved it through the same unit distance (as a result of its acceleration being less from F = ma), and this would have resulted in more work having been done. This contradicts the accepted relation, Work Done = Force x Distance.

That's from its definition.
You've missed out the essential point: PER UNIT OF MASS
Work Done = Force x MASS x Distance
W1 = F*M*D
W2 = 2*F*M*D
Therefore the work done in the second case is twice as much.

That's from its definition.
You've missed out the essential point: PER UNIT OF MASS
Work Done = Force x MASS x Distance
W1 = F*M*D
W2 = 2*F*M*D
Therefore the work done in the second case is twice as much.

You'd best set yourself to re-evaluating where you stand.

In my physics book, and yes I do actually own one which I have read again and again in the relevant sections, work is always quoted as equal to force multiplied by distance.

W.D. = F x d

I have never heard of this equation W.D. = F x m x d and believe you have just made it up in a vain effort to win the argument.

In my physics book, and yes I do actually own one which I have read again and again in the relevant sections, work is always quoted as equal to force multiplied by distance. W.D. = F x d I have never heard of this equation W.D. = F x m x d and believe you have just made it up in a vain effort to win the argument. Nice try but no.......I suggest you read a physics book yourself carefully. And yes you do score a FAIL.

Text books quoting FORCE are doing so in terms of MASS x ACCELERATION being FORCE. They are talking about LIFTING WEIGHTS, and as you know, the WEIGHT of a body is actually its mass times its acceleration due to gravity.
Hence the true equation is as I have said Work done = Distance x Mass x Acceleration (frequently G). In space (free of fields) this still applies. The acceleration is whatever is imparted to the mass over the particular distance.
It's something that most people intuit, but apparently you don't. This "intuition" has allowed most physics book writers to abbreviate what they mean to the point where it's possible to misunderstand. It really should be obvious to you that pushing an object twice as heavy as another object should involve twice as much work. More obvious, surely, than suddenly imagining you had discovered a new branch of physics.
In your options, the second requires twice as much work as the first.
And you're still as wrong as you were before. You aren't reading what I'm writing.
You may think what you like. If you're in a permanent mess because you can't see it any other way, this will be quite to my taste. I like seeing hubris.

Text books quoting FORCE are doing so in terms of MASS x ACCELERATION being FORCE. They are talking about LIFTING WEIGHTS, and as you know, the WEIGHT of a body is actually its mass times its acceleration due to gravity.
Hence the true equation is as I have said Work done = Distance x Mass x Acceleration (frequently G). In space (free of fields) this still applies. The acceleration is whatever is imparted to the mass over the particular distance.
It's something that most people intuit, but apparently you don't. This "intuition" has allowed most physics book writers to abbreviate what they mean to the point where it's possible to misunderstand them.
It really should be obvious to you that pushing or lifting an object twice as heavy as another object should involve twice as much work. More obvious, surely, than suddenly imagining you had discovered a new branch of physics.
In your options, the second requires twice as much work as the first.
And you're still as wrong as you were before. You aren't reading what I'm writing.
You may think what you like. If you're in a permanent mess because you can't see it any other way, this will be quite to my taste.